1. Field of the Invention
The present invention relates to an information processing apparatus having a function of displaying current constraint information, a method of operating the apparatus and a computer readable information recording medium storing a program for performing the method.
2. Description of the Related Art
Generally speaking, a printer has available printing settings which are different among particular machine types. In many cases, a performance of a printer varies according to a configuration of available options mounted therein. As optional functions of a printer, there are a sorting function, a stapling function, a punching function, a booklet printing function and so forth.
Especially for printers, there are many functions which are available only exclusively, in comparison to other machines. For example, a function of right-edge stapling and a function of booklet printing are only exclusively available. In a graphical user interface (GUI) of a printer driver, generally speaking, in order to achieve exclusion among respective available capabilities or among respective available functions of a printer, very complicated constraint processing may be carried out. The constraint processing means to control so that mutually exclusive functions are prevented from being set by a user at the same time. Because the constraint processing may be complicated as mentioned above, a user may be confused as to why a particular function is not available, when the particular function which is an optional function is not available due to the constraint processing. Further, in such a case, the user may not have a specific way to solve the problem to make the particular function available, i.e., as to which other setting for example should be changed and how to carry out such a change. Therefore, a new technique has been developed for making it possible to display to a user a reason why the particular function is not available.
For example, Japanese Laid-Open Patent Application 2000-225754 discloses a method. In this method, constraint processing is described in an external file, and, in order to rationally carry out constraint processing of a user interface (UI) of a driver, the external file has two areas. In a first area, constraint processing which is common among respective machine types is descried. In a second area, constraint processing which is unique for each particular machine type is described. Then, in the file, ‘constraint data’ of parameters are included, and in the constraint data, a ‘constraint condition list and language of messages to display’ are included. In this method, constraint processing is carried out in consideration of not only combinations of designated parameters but also all or part of parameter-designating permutations. Also, in this method, constraint information is described in a setting file, and a message can be created logically. Therefore, constraint processing can be carried out flexibly to adapt to various cases, and thus, user friendliness improves.
However, in this method, actual contents of messages to display are prepared for each function as fixed contents. Thus, in each message, all the possible causes by which the function or an option of the function is subject to constraint are listed. A user cannot understand which one thereof is a true reason by which the function is currently unavailable. Further, in this method, actual contents of messages should be prepared for each machine type. Therefore, there may be a possibility that an error occurs in the contents of the messages.